Abstract
Human exposure to heavy metals is one of the leading public health concerns these days. The entrance of heavy metals
in agricultural products through untreated wastewater is a major source that causes food chain contamination and
affects humans and the environment. On the outskirts of Karachi, vegetables are cultivated on a large scale using
untreated wastewater of Lyari and Malir Rivers. The present study conducted to assess levels of five heavy metals i.e.
Arsenic (As), Chromium (Cr), Copper (Cu), Nickel (Ni) and Lead (Pb) in commercially available vegetables in
Karachi, Pakistan. The selected vegetables found contaminated with heavy metals but in different orders i.e. in spinach,
the contamination of heavy metals was in order of (Pb > Cu > As >Cr > Ni), lettuce (Ni > Pb > Cr > Cu > As), cabbage
(Pb > Cu > As > Ni > Cr), spring onion (Pb > Cu > As > Cr > Ni), gourd (Pb > Cu > Ni > As > Cr), okra (Ni > Pb > Cr
> Cu > As) and eggplant (Pb > Ni > Cr > Cu > As). The chronic exposure to these toxic metals via food may cause
various clinical manifestations, damage vital organs and produce cancers. Moreover, the authors recommend banning
the use of untreated wastewater for agricultural practices in Karachi.
